The first Hammarlund plant was a loft operation engaged in radio component manufacturing on
Fulton Street in
Lower Manhattan, New York City. Their
variable capacitor designs quickly became industry standards, and the component's schematic symbol was adopted as the company's logo. In the mid-1920s, Hammarlund formed a partnership called Hammarlund-Roberts Co. specifically to offer kits for AM broadcast radios using Hammarlund parts.
Comet pro receiver When Hammarlund-Roberts went out of business in 1931, Hammarlund Mfg. Co., Inc. entered into the
shortwave receiver market with the introduction of the "Comet Pro", the first commercial short wave
superheterodyne receiver. Professional listening post installations made great use of the Comet Pro, and it was used also on many major exploration expeditions.
Communications gear While Hammarlund was most famous for its amateur/short-wave receiver lines such as the Super Pro series and the HQ series (which includes the HQ-100, 110, 120, 129, 145, 150, 160, 170, 180, 200 and 215),{{cite journal |journal=
QST |publisher=The American Radio Relay League |author=George J. Misic, KE8RN |title=The Hammarlund HQ-170 and HQ-180 Hammarlund also built a substantial quantity of the VHF FM "Village Radios" for the
United States Agency for International Development (AID) to use in
Vietnam, as well as a number of land-mobile radios and transceivers for the
Citizens band radio market.
Final decades Even as the company continued to produce communications equipment for the amateur, commercial, and Citizens Band radio markets, it underwent frequent changes of ownership. The first was in the late 1950s when Hammarlund was sold to Telechrome. Several years later Telechrome sold out to Giannini Scientific. In the late 1960s, the company was once again sold to the Electronic Assistance Corporation (EAC). But, this sale was final. The product line was sold off in parts or phased out. The Cardwell Condenser Corporation purchased all remaining stocks, and in 1973 the Hammarlund factory closed. At the time of its dissolution, Hammarlund was among the USA's very oldest producers of radio equipment. Today, many Hammarlund radios are collected, restored and used by
vintage amateur radio enthusiasts. ==Hammarlund legend==